PERCY, HENRY ALGERNON, sixth Earl of Northumberland (1502?–1537), was eldest son of Henry Algernon, fifth earl [q. v.], by Catherine, daughter of Sir Robert Spencer. He was born about 1502, and sent, when quite young, to be a page in Wolsey's household. He was knighted in 1519, and, in spite of the fact that his father had destined him as early as 1516 (Letters and Papers, Hen. VIII, ii. i. 1935) for the daughter of the Earl of Shrewsbury, he fell in love with Anne Boleyn, then a young lady about the court. The intrigue was soon discovered, and the Earl of Northumberland sent for. Wolsey himself, though ignorant as yet of the king's inclinations, scolded the young man. Lord Percy gave way, but there is little doubt that the attachment lasted through his life. In July 1522 he was made a member of the council of the north; in October he was made deputy warden of the east marches, and Dacre suggested that, young as he was, he should be made warden the same year. On 19 May 1527 he succeeded his father as sixth Earl of Northumberland; he was made steward of the honour of Holderness on 18 June; on 2 Dec. he became lord warden of the east and west marches.

Northumberland had many misfortunes. He was constantly ill from a kind of ague. He was burdened with debt, and yet had to keep up a vast establishment and engage in much fighting on his own account. Wolsey treated him like a boy so long as he was in power. He was not often allowed to go to the court, nor even to his father's funeral. To add to his other distresses, he disagreed with his wife, who soon returned to her father, and hated her husband heartily for the rest of his short life. Many of his troubles are reflected in his letters (cf. Skelton, Why come ye not to Court?). His chief friend was Sir Thomas Arundell [q. v.]

In spite of his anxieties he was very active on the borders. He had leave in 1528 to come to London, Wolsey writing that he hoped he would prove ‘conformable to his Hyghness's pleesor in gyvyng better attendaunce, leaving off his prodigality, sulleness, mistrust, disdayne, and making of partys.’ In 1530, while he was at Topcliffe, he received a message from the king ordering him to go to Cawood and arrest Wolsey. He seems to have acted as humanely as he could, and sent his prisoner south in the custody of Sir Roger Lascelles, while he remained to make an inventory of the cardinal's goods. He was one of the peers who signed the letter to the pope in July 1530 asking that the divorce might be hurried on, and, from his friendship with Sir Thomas Legh [q. v.], it seems as though he were of the new way of thinking in religious matters. On 23 April 1531 he was created K.G.; on 11 May 1532 he was made sheriff of Northumberland for life; and on the 26th of the same month a privy councillor. In 1532 Northumberland stood in great peril. His wife, drawing, doubtless, upon her recollection of matrimonial squabbles, accused him of a precontract with Anne Boleyn. She confided her alleged grievance to her father, who cautiously mentioned the matter to the Duke of Norfolk. Anne Boleyn ordered a public inquiry. Northumberland denied the accusation, and his accusers were routed.

Northumberland took part in the trial of Lord Dacre in July 1534. In the January following he was accused of ‘slackness’ on the borders, and also of the graver offence of having a sword of state carried before him when he went as justiciary to York. Illness was doubtless in part responsible for his neglect of duty in the previous year. But Chapuys ranked him, on information which he had from his doctor, among the disaffected early in 1535. Having no children, Northumberland now began to arrange his affairs. In February 1535 he wrote to Cromwell that the king had given him leave to name any of his blood his heir; but, on account of their ‘debylytery and unnaturalness,’ he had determined to make the king his heir. This decision he confirmed later. In 1536 he was created lord president of the council of the north, and vicegerent of the order of the Garter. In May 1536 he formed one of the court for the trial of Anne Boleyn, but when he saw her he grew ill and left the room. Anne is said to have confessed a pre- contract with him in the hope of saving her life. In September 1536 he had a grant of 1,000l. to come to London in order to make arrangements about his lands. The matter had not been completed when the northern rebellion known as the ‘pilgrimage of grace’ broke out. Northumberland's brothers and mother were open sympathisers with the rebels, but the earl himself remained loyal. The rebel leader, Aske, and his men came to Wressell, where he was ill in bed. The earl, who is spoken of as ‘Crasyside,’ was besought to resign his commands of the marches into the hands of his brothers, or at all events go over to the rebels. He refused both requests; and when William Stapleton, in whose depositions we have an account of the affair, went up to see him, ‘he fell in weeping, ever wishing himself out of the world.’ Aske sent him to York, to protect him from the fury of his followers, who wanted to behead him. Finding himself ‘for ever unfeignedly sick,’ he made a grant to the king of his estates, on condition that they might pass to his nephew. When, however, his brother, Sir Thomas, was attainted, he made the grant unconditional in June 1537. By this time his mind was fast failing. He removed to Newington Green, where Richard Layton [q. v.] visited him on 29 June 1537. He says that he found him ‘languens in extremis, sight and speech failed, his stomach swollen so great as I never see none, and his whole body as yellow as saffron.’ He died on 29 June 1537, and was buried in Hackney church. Weever quotes an inscription, but Bishop Percy in 1767 could find no trace of it. He married, in 1524, Mary Talbot, daughter of George, fourth earl of Shrewsbury, but left no issue. The earldom fell into abeyance on his death, but was revived in favour of his nephew Thomas, seventh earl [q. v.] His widow lived until 1572. She had a grant of abbey lands, and was suspected of being a Roman catholic, a favourer of Mary Queen of Scots, and of hearing mass in her house. She was buried in Sheffield church.

Northumberland's two brothers, Sir Thomas and Sir Ingelram Percy, took an active part in the management of his estates. They were both important leaders in the pilgrimage of grace. Both were taken prisoners. Sir Thomas was attainted and executed in 1537. His sons, Thomas, seventh earl [q. v.], and Henry, eighth earl [q. v.], are separately noticed. Sir Ingelram Percy was confined in the Beauchamp Tower, where his name is to be seen cut in the stone. But he was soon liberated, went abroad, and died about 1540. He left an illegitimate daughter Isabel, who married, in 1544, Henry Tempest of Broughton.